1) Ticket cost for 60 passengers = 4000 - (60 - 50)(50) = 4000 - 10(50) = R3500
2) Price of ticket for over 50 = R [ 4000 - 50x ]
3) The revenue, R = number of passengers * cost of a ticket
(50 + x)(4000 - 50x) = 20000 + 4000x - 2500x - 50x^2 = 200000 + 1500x - 50x^2
4) In the form ax^2 + bx + c
The number of passengers that will provide the max revenue is -b/[2a]
So we have
R = -50x^2 + 1500x + 200000
So......the number of passengers providing the max revenue is :
(-1500) / (2 * -50) = -1500/ -100 = 15 passengers = 15 over 50 = 65 passengers
EDIT TO CORRECT A SILLY ERROR !!!
